Abstract
From the ethanolic extract of the aerial parts of
Centaurea scoparia four new sesquiterpene lactones, belonging to the guaiane class, were isolated and identified, together with a known germacranolide. The structures were elucidated by spectroscopic methods including one- and two-dimensional NMR studies. The relative configuration was deduced from the 2D NOESY spectra. CD spectroscopy of the chlorinated compounds was used for determination of their absolute configuration.